mkcert is not amd64 only

[AndreiCherniaev]

Bad advice is detected in readme

mkcert/README.md

Line 81 in 1c1dc4e

curl -JLO "https://dl.filippo.io/mkcert/latest?for=linux/amd64"

We should avoid hard-coded to architecture. Don't say this is just example. Even smart Canonical peoples copy-past it.

I see two options to fix:

1. Make if-then script based on dpkg --print-architecture output or similar relative to OS
2. The best idea is to use well-known tools to download from github, for example, binup.
   Examples how to use binup

sudo ./binup install --project mxmlnkn/rapidgzip --path '/usr/bin'
./binup -v install --project FiloSottile/mkcert

But mkcert should be packed in archive!

So regardless to architecture, I suggest to put mkcert release in tar.gz. In this case we can avoid chmod +x /usr/local/bin/mkcert and use binup. Github release in archive is de-facto standard, most of popular software use this way (example1, example2).